I've just done this chart for a pupil and posting it here in case it's useful for anyone else.
It's tricky if you are new to learning to read music at the same time as learning to play the harp. Very easy to get confused when the left hand of the music jumps about between bass clef and treble clef and you are reading ledger lines. It can take a while to work out which octave a note is in!
For those new to reading music and harp playing - harpists tend to only use 3-4 ledger lines maximum. Advanced players will read more ledger lines, but 3 is absolutely fine for beginners and intermediate harpists and there is no need to learn to read notes with more ledger lines than that.
Composers - If a note needs more than 3 ledger lines than change to a different clef where there aren't any - or use the 8va or 8vb. If you can avoid using ledger lines by using the 8va or 8vb then it's good practice to do so.
This chart has lots of ledger lines that we wouldn't normally use and are there just for note comparison.
Hopefully this chart will help those new to the harp who are also learning to read music at the same time.